12 - Electrolytes/Acid-base Imbalances Flashcards
Where do we find electrolyes?
In the blood or within the cell
The most common cation in ECF
Na+
Passive diffusion on Na occurs
between IVF and ISF
Hyponatremia
decreased serum sodium levels (direct sodium loss or excess water in extracellular compartment (dilution))
What causes hyponatremia
excessive sweating, vomiting, diarrhea, diuretic drugs and low sodium diet, hormone imbalances, renal failure, excess water intake
Effects of hyponatremia
- impaired nerve conduction
- lowered osmotic pressure, fluid shift, hypovolemia, low bp
- swelling of brain
Hypernatremia
high sodium levels (ingestion of sodium, loss of water from body faster than sodium loss)
What causes hypernatremia
insufficient ADH, loss of thirst mechanism, water diarrhea, periods of rapid respiration
Effects of hypernatremia
- weakness, agitation
- firm subcutaneous tissues
- thirst + dry mouth
- edema
- elevated bp
- decreased urine output (ADH secreted)
Effects of hypernatremia exception
if insufficient ADH is the primary cause there will be increased urine output
Most common cation in ICF
K+
Decrease in potassium level
Hypokalemia
Hypokalemia is due to
- diarrhea
- diuretics
- excess aldosterone
- decreased intake
Effects of hypokalemia
- cardiac dysrhythmias
- muscle weakness
- paresthesias
- decreased GI tract motility
- shallow respirations
- decreased renal function (polyuria)
Hyperkalemia
an increase in potassium levels
Hyperkalemia is due to
- renal failure
- aldosterone deficit
- use of potassium sparing diuretic
- decreased excretion of potassium
- burn/crush injury
- acidosis
Effects of hyperkalemia
- dysrhythmias
- muscle weakness
- fatigue, nausea
- paresthesias
Why is calcium an important cation in ECF?
- levels are controlled by parathyroid hormone and calcitonin
- but also influenced by vitamin D and phosphate ion levels
What does Ca+ do?
- strength for bones and teeth
- maintains excitability and permeability required for nerve conduction
- enable muscle contraction
- required for clotting process
Causes of hypocalcemia
- decreased parathyroid hormone
- decreased dietary intake of calcium
- malabsorption syndrome
- vit d deficit
- alkalosis
- elevated serum phosphate levels
Effects of hypocalcemia
- tetany (muscle spasms)
- tingling fingers
- mental confusion, irritability
- arrhythmias, weak heart contraction
Causes of hypercalcemia
- bone tumors
- hyperparathyroidism
- immobility
- excess intake
Effects of hypercalcemia
- apathy, lethargy
- anorexia, nausea, constipation
- polyuria, thirst
- kidney stones
- arrhythmias, prolonged strong contractions
- increased bp
Hypomagnesemia (rare) due to
malabsorption or malnutrition
Hypermagnesemia (rare) due to
renal failure
Effects of hypomagnesemia
- tremors, involuntary movements
- insomnia
- increased heart rate
- personality changes
Effects of hypermagnesemia
- decreased reflexes
- lethargy
- cardiac arrhythmias
Hypophosphatemia due to
malabsorption, diarrhea, use of antiacids
Effects of hypophosphatemia
- tremors, weak reflexes
- paresthesias
- confusion
- dysphagia
- decreased clotting + phagocytosis
Hyperphosphatemia due to
renal failure, tissue damage, chemotherapy
Effects of hyperphosphatemia
same as hypocalcemia
Chloride imbalances follow
sodium
Hypochloremia cause and effect
- dehydration
- vomiting (loss of acid), excessive perspiration
Hyperchloremia
edema and weight gain, increased intake of sodium chloride
Why does the body is naturally move towards acidosis?
Cells are constantly metabolizing, constantly producing carbon dioxide and carbonic acid
Acidosis
- increased H+
- pH under 7.35
- death at pH 6.8
Alkalosis
- decreased H+
- pH over 7.45
- death at pH 7.8
What regulates acids and bases to maintain a normal pH?
hydrogen ion regulates how acidic or basic the body’s fluid is
high H is
acidic
low H is
alkaline
normal pH range
7.35 - 745
3 major mechanisms for maintenance of pH
buffer systems, exhalation of co2, kidney excretion
buffer systems
chemical buffers in blood combine with offending acid or base neutralizing harmful effects
Exhalation
higher rate and depth of breathing=more co2 exhaled= low carbonic acid levels
Kidney excretion
slowest mechanism, secretes hydrogen in the urine and reabsorbs bicarbonate and can synthesize bicarbonate ions
